Half of the answer you have already answered and that is what will your current landlord allow.
As far as the seller, it depends.
If the home you like is a bank owned foreclosure then they very highly unlikely that they will wait. On the other hand if it is still a private individual owner then it possibly could be negotiated. It may also be possible to get them to pay that $1250 to your landlord.
You need an agent to help you through the process. DO NOT use the listing agent! I'll be glad to help if you like and I'm sure thatseveral other agents will chime in here and offer to help as well.
Just remember that if you close in October, your first mortgage payment would not be due until December 1st. Rather than paying an early termnation fee of $1,250, it would probably make more sense to just pay the regular rent for November unless your rent is more than that amount.
Rodney Mason, NMLS #151088
Sr Loan Officer
825 Juniper St NE, Atlanta, GA 30308
Office: (404) 591-2453
Apply Online at http://www.rodneymason.com
Licensed in Alabama & Georgia
Have your Realtor put a Closing Date on the Escrow of Nov. 12th (which would be a 72 day Escrow.
They will spend a week arguing about it, and it'll be a 66 day Escrow.
Ask for 30 days for Loan and Appraisal Contingencies to reinforce the last Escrow.
If you're going to push on this, do not push on other details, like price.